JP2002181556A - Thinning-out apparatus for positional data - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a recording capacity by leaving only effective positional data in a position calculation terminal such as a navigation system or the like. SOLUTION: In the position calculation terminal, an absolute position detection sensor such as a GPS or the like, a distance sensor such as a vehicle-speed pulse sensor or the like and an angular velocity sensor or the like such as a vibrating gyro or the like are used, and the position of a moving object is calculated by a position calculation means 1. The accuracy of position of the moving object is calculated by an accuracy-of-position calculation means 2. When an error in the position is judged to be less than a threshold value by a position recording and judgment means 3, a position recording means 4 records the position in a memory. Only the effective positional data is left so as to reduce a data amount. Thereby, the recording capacity of positional data required for displaying a running track can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position data thinning device, and more particularly, to a position data thinning device used in an on-vehicle navigation system or an emergency notification system.

[0002]

2. Description of the Related Art A conventional navigation device has a traveling locus display function for displaying a road on which a user has traveled. The position data forming the traveling locus is recorded in the memory.

[0003] In addition, there is an emergency notification system that supports a request for dispatch of a rescue agency when an emergency such as a car accident due to a car or sudden illness of a passenger occurs. In this system,
In order to notify the rescue agency of the notification position, the travel locus (position data) obtained by the position calculation device mounted on the car is
It is transmitted wirelessly using a mobile phone or the like.

[0004]

However, in the conventional navigation system, a large-capacity memory for storing position data corresponding to a long traveling distance is required to display a traveling locus as long as possible. There was a problem.

Further, in the conventional emergency notification system, if the position data of the traveling locus to be transmitted is large, the data communication time becomes longer, and consequently the time required for notifying the rescue organization of the notification position becomes longer. was there. Conversely, if the position data is simply reduced, it becomes difficult to determine which road the vehicle has traveled, and as a result, there has been a problem that an accurate notification position may not be obtained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and reduce the capacity of a memory for recording position data necessary for displaying a traveling locus while leaving only valid position data. It is another object of the present invention to reduce the amount of position data and reduce the time required to transmit position data required for specifying the position where an accident has occurred.

[0007]

In order to solve the above-mentioned problems, according to the present invention, a position data thinning device includes at least one of an absolute position detecting sensor, a distance sensor, and an angular velocity sensor.
Position calculating means for calculating the position of the moving body by using one of them, position recording means for recording the calculated position data, distance recording means for recording the moving distance or the accumulated traveling distance at the calculated position, A position transmitting unit that wirelessly transmits a plurality of position data calculated retroactively; and a position transmission determining unit that determines whether to transmit the position data based on a moving distance until a certain time is reached. .

[0008] With this configuration, by detecting position data with high accuracy and recording only the position data in the memory, it is possible to reduce the memory amount of the position data to be recorded for displaying the traveling locus. Further, since the position data can be reduced as the distance from the notification position increases, the time required for transmitting the position data can be reduced.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to FIGS.

(First Embodiment) A first embodiment of the present invention is a position data thinning-out apparatus which calculates the position accuracy of a calculated position and determines whether or not to record the position based on the position accuracy. is there.

FIG. 1 is a functional block diagram showing the configuration of the position data thinning device according to the first embodiment of the present invention. In FIG. 1, a position calculating means 1 is a means for calculating a position of a moving body using an absolute position detecting sensor such as a GPS, a distance sensor such as a vehicle speed pulse, an angular velocity sensor such as a vibration gyro, and the like. The position accuracy calculation means 2
This is a means for calculating the accuracy of the position obtained by an absolute position detection sensor such as S, a distance sensor such as a vehicle speed pulse, and an angular velocity sensor such as a vibration gyro. The position record determination means 3 is a means for determining whether the position error is equal to or greater than a threshold. The position recording means 4 is means for recording the position on a memory or a recording medium.

The operation of the position data thinning device according to the first embodiment of the present invention configured as described above will be described. The position calculation means 1 calculates the position of the moving body using an absolute position detection sensor such as a GPS, a distance sensor such as a vehicle speed pulse, an angular velocity sensor such as a vibration gyro, and the like. If there is a digital map, the position of the moving object may be calculated by performing map matching with the road recorded on the digital map using the sensor information.

The position accuracy calculation means 2 includes an absolute position detection sensor such as a GPS, a distance sensor such as a vehicle speed pulse,
The accuracy of the position determined by an angular velocity sensor such as a vibrating gyroscope is calculated. The position accuracy required here is
It can be represented by the sum of (A) the position error by the absolute position detection sensor and (B) the position error by the relative position detection sensor. The position error of (A) can be estimated from an error due to a geometrical arrangement by GPS satellites, the number of satellites used for positioning, and the like. (B) is divided into a distance error and a turning angle error. The distance error is an error of the moving distance obtained by a sensor that detects the moving distance such as a vehicle speed pulse, but the error remains even if the error is corrected by any correction means. Therefore, the residual error of the distance increases with time.

The same applies to the error of the turning angle. The error also remains in the angular speed obtained by a sensor for detecting the angular speed such as a vibrating gyroscope, and the residual error of the turning angle increases with time. Under such an assumption, the error of the relative position detection sensor can be estimated.

The position and position error obtained in this way are input to the position recording judging means 3. Position record determination means 3
Then, if the position error is equal to or greater than a certain threshold value, it is determined that the position accuracy of the calculated position is low, and is not output to the position recording means 4. Conversely, if the position error is smaller than a certain threshold, the position recording determination unit 3 determines that the calculated position accuracy is high, and outputs it to the position recording unit 4.

The position recording means 4 records the inputted position in, for example, a memory or a recording medium. Since the capacity for recording the position is limited, if the recording area exceeds the predetermined recording area, the recording is returned to the head of the recording area.

As described above, in the first embodiment of the present invention, the position data thinning device calculates the position accuracy of the calculated position and determines whether or not to record the position based on the position accuracy. Therefore, by detecting position data with high position accuracy and recording only the position data in the memory, it is possible to reduce the memory amount of the position data to be recorded for displaying the traveling locus.

(Second Embodiment) A second embodiment of the present invention is a position data thinning-out apparatus which calculates the azimuth accuracy of the calculated position and determines whether or not to record the position based on the azimuth accuracy. is there.

FIG. 2 is a functional block diagram showing the configuration of the position data thinning device according to the second embodiment of the present invention. In FIG. 2, an azimuth accuracy calculating unit 5 is a unit that calculates the azimuth accuracy obtained by an absolute azimuth detection sensor such as a GPS or an angular velocity sensor such as a vibration gyro.

The operation of the position data thinning device according to the second embodiment of the present invention configured as described above will be described. The operation of the position calculating means 1 is the same as in the first embodiment. The azimuth accuracy calculating means 5 calculates the azimuth accuracy obtained by an absolute azimuth detection sensor such as a GPS and an angular velocity sensor such as a vibration gyro.

The azimuth accuracy obtained here can be expressed by the sum of (A) the azimuth error by the absolute azimuth detection sensor and (B) the azimuth error by the relative position detection sensor. (A)
Can be estimated from the traveling speed or the like. The azimuth error of (B) is the azimuth obtained by GPS,
Even if the correction is performed using the direction of the road recorded on the digital map, an error remains in the angular velocity obtained by a sensor for detecting the angular velocity such as a vibrating gyroscope, and the residual error of the turning angle increases with time. Under such an assumption, the error of the relative position detection sensor can be estimated.

The position and azimuth error obtained in this way are inputted to the position record judging means 3. When the azimuth error is equal to or greater than a certain threshold value, the position recording determination unit 3 determines that the calculated position accuracy of the position is low.
Not output to This is because it can be determined that if the azimuth accuracy is poor, there is a possibility that a correct position may not be obtained. Conversely, when the azimuth error is smaller than a certain threshold, the position recording determination unit 3 determines that the calculated position accuracy is high, and outputs it to the position recording unit 4. The operation of the position recording means 4 is the same as in the first embodiment.

As described above, in the second embodiment of the present invention, the position data thinning device calculates the azimuth accuracy of the calculated position and determines whether to record the position based on the azimuth accuracy. Therefore, by detecting position data with high azimuth accuracy and recording only the position data in the memory, the amount of memory of position data to be recorded for displaying the traveling locus can be reduced.

(Third Embodiment) In a third embodiment of the present invention, the number of GPS satellites used for positioning is calculated, and whether to record a position is determined based on the number of satellites used for positioning. This is a position data thinning device.

FIG. 3 is a functional block diagram showing the configuration of the position data thinning device according to the third embodiment of the present invention. In FIG. 3, the positioning satellite number calculating means 6 is a means for calculating the number of GPS satellites used for detecting the absolute position.

The operation of the position data thinning device according to the third embodiment of the present invention configured as described above will be described. The operation of the position calculating means 1 is the same as in the first embodiment. The positioning satellite number calculating means 6 calculates the number of satellites used for detecting an absolute position, such as GPS satellites.

The position thus obtained and the number of satellites used for positioning are input to the position record determining means 3. When the number of positioning satellites is less than a certain threshold value, the position record determining means 3 determines that the calculated position accuracy is low, and does not output it to the position recording means 4. This is because places with a small number of positioning satellites are likely to be places where the sky can not be seen,
This is because, in some cases, it is possible to determine that there is a possibility that a high-accuracy position may not be obtained, for example, a radio wave from a satellite is reflected by a high-rise building or the like, and a large position error occurs due to multipath. Conversely, if the number of positioning satellites is equal to or greater than a certain threshold, the position record determining means 3 determines that the calculated position accuracy is high, and outputs it to the position recording means 4. The operation of the position recording means 4 is the same as in the first embodiment.

As described above, in the third embodiment of the present invention, the position data thinning device uses the GPS
By calculating the number of satellites and determining whether to record the position based on the number of satellites used for positioning, it is possible to detect position data with a large number of positioning satellites and record only that position data in memory. In addition, the amount of memory of position data to be recorded for displaying the traveling locus can be reduced.

(Fourth Embodiment) A fourth embodiment of the present invention detects whether positioning by a GPS satellite is successful, and determines whether or not to record a position based on the presence or absence of positioning by a GPS satellite. Is a position data thinning device.

FIG. 4 is a functional block diagram showing the configuration of the position data thinning device according to the fourth embodiment of the present invention. In FIG. 4, the satellite positioning presence / absence detecting means 7
This is a means for detecting whether or not the positioning by the S satellite was successful.

The operation of the position data thinning device according to the fourth embodiment of the present invention configured as described above will be described. The operation of the position calculating means 1 is the same as in the first embodiment. Also, the satellite positioning presence / absence detecting means 6
It calculates whether or not positioning has been performed by a positioning satellite such as S, or the percentage of time during which GPS positioning has been performed within a certain fixed time.

The position thus determined, the presence / absence of satellite positioning, and the ratio of satellite positioning during a certain period of time are input to the position record determining means 3. In the position record determination means 3, when positioning by satellite is not performed, or
If the ratio of positioning by satellite in a certain time period is less than a threshold value, it is determined that the position accuracy of the calculated position is low, and is not output to the position recording means 4. This is because if satellite positioning is not performed, or if satellite positioning is not performed frequently, the sky is likely to be a place where the sky cannot be overlooked. This is because it is possible to determine that there is a possibility that a highly accurate position may not be obtained, for example, a radio wave is reflected and a large position error occurs due to multipath. vice versa,
The position record determining means 3 determines that the accuracy of the calculated position is high when the positioning by the satellite is performed or when the ratio of the positioning by the satellite in a certain time is equal to or more than a certain threshold value. Output to recording means 4. The operation of the position recording means 4 is the same as in the first embodiment.

As described above, in the fourth embodiment of the present invention, the position data thinning device detects whether the positioning by the GPS satellite is successful, and determines whether or not to record the position by the GPS satellite. Since the configuration is determined based on the presence / absence, it detects the position data where satellite positioning is performed or the ratio of satellite positioning performed during a certain period of time is high, and records only that position data in the memory, so that the vehicle travels. It is possible to reduce the amount of memory for position data to be recorded for displaying the trajectory.

(Fifth Embodiment) A fifth embodiment of the present invention is directed to a position data thinning device which calculates the position accuracy of the calculated position and determines whether or not to transmit the position based on the position accuracy. is there.

FIG. 5 is a functional block diagram showing a configuration of a position data thinning device according to a fifth embodiment of the present invention. In FIG. 5, a position transmission determining means 8 is a means for determining whether or not to transmit a position based on positional accuracy. The position transmitting means 9 is means for converting the position data into a format that allows digital wireless communication and transmitting the converted data to a rescue agency or the like.

The operation of the position data thinning device according to the fifth embodiment of the present invention configured as described above will be described. The operation of the position calculating means 1 is the same as in the first embodiment. The operation of the position accuracy calculating means 2 is the same as in the first embodiment.

The position recording means 4 records the position obtained by the position calculating means 1 and the position accuracy obtained by the position accuracy calculating means 2 in, for example, a memory or a recording medium. Since the capacity for recording the position is limited, if the recording area exceeds the predetermined recording area, the recording is returned to the head of the recording area.

When transmitting position data recorded in the past T (T may be variable) time (or minute, second) from a certain point in time to, for example, a rescue organization, the position transmission determining means 8 Read the information of the position and the position accuracy. When the position error is equal to or larger than a certain threshold, the position transmission determining means 8 determines that the calculated position accuracy is low and does not output the calculated position to the position transmitting means 9. Conversely, when the position error is less than a certain threshold, the position accuracy of the calculated position is determined to be high, and the calculated position is output to the position transmitting means 9.

The position transmitting means 9 converts the position data output by the position transmission judging means 8 into a format that allows digital wireless communication, and transmits the position data to a rescue agency or the like.

As described above, in the fifth embodiment of the present invention, the position data thinning device calculates the position accuracy of the calculated position and determines whether to transmit the position based on the position accuracy. Therefore, by detecting position data with high position accuracy and transmitting only the position data, the time required to transmit the position data to a rescue agency or the like can be reduced.

(Sixth Embodiment) A sixth embodiment of the present invention is a position data thinning-out apparatus that calculates the azimuth accuracy of the calculated position and determines whether to transmit the position based on the azimuth accuracy. is there.

FIG. 6 is a functional block diagram showing the configuration of the position data thinning device according to the sixth embodiment of the present invention. In FIG. 6, a position calculating unit 1 and an azimuth accuracy calculating unit 5 are the same as those in the first or second embodiment.

The operation of the position data thinning device according to the sixth embodiment of the present invention configured as described above will be described. The operation of the position calculating means 1 is the same as in the first embodiment. The operation of the azimuth accuracy calculating means 5 is the same as in the second embodiment.

The position recording means 4 records the position obtained by the position calculating means 1 and the azimuth accuracy obtained by the azimuth accuracy calculating means 5 in, for example, a memory or a recording medium.

When transmitting position data recorded in a past T (T may be variable) time (or minute, second) from a certain point in time to, for example, a rescue organization, the position transmission determining means 8 The information of the position and the azimuth accuracy is read out. When the azimuth error is equal to or greater than a certain threshold, the position transmission determining unit 8 determines that the calculated position accuracy is low, and does not output the calculated position accuracy to the position transmitting unit 9. Conversely, if the azimuth error is less than a certain threshold, the position accuracy of the calculated position is determined to be high and output to the position transmitting means 9. The operation of the position transmitting means 9 is the same as that of the fifth embodiment.

As described above, in the sixth embodiment of the present invention, the position data thinning device calculates the azimuth accuracy of the calculated position and determines whether or not to transmit the position based on the azimuth accuracy. Therefore, by detecting position data with high azimuth accuracy and transmitting only the position data, the time required to transmit the position data to a rescue agency or the like can be reduced.

(Seventh Embodiment) In a seventh embodiment of the present invention, the number of GPS satellites used for positioning is calculated, and whether to transmit a position is determined based on the number of satellites used for positioning. This is a position data thinning device.

FIG. 7 is a functional block diagram showing the configuration of the position data thinning device according to the seventh embodiment of the present invention. In FIG. 7, a position calculating means 1 and a positioning satellite number calculating means 6 are the same as those in the first or third embodiment.

The operation of the position data thinning device according to the seventh embodiment of the present invention configured as described above will be described. The operation of the position calculating means 1 is the same as in the first embodiment. The operation of the positioning satellite number calculation means 6 is the same as that of the third embodiment.

The position recording means 4 records the position obtained by the position calculating means 1 and the number of positioning satellites obtained by the positioning satellite number calculating means 6 in, for example, a memory or a recording medium.

When transmitting position data recorded in the past T (T may be variable) time (or minute, second) from a certain point in time to, for example, a rescue organization, the position transmission determining means 8 The information of the determined position and the number of positioning satellites is read. If the number of positioning satellites is less than a certain threshold, the position transmission determining means 8 determines that the calculated position accuracy is low, and does not output it to the position transmitting means 9. Conversely, if the number of positioning satellites is equal to or greater than a certain threshold value, it is determined that the position accuracy of the calculated position is high, and the calculated position is output to the position transmitting means 9. The operation of the position transmitting means 9 is the same as that of the fifth embodiment.

As described above, in the seventh embodiment of the present invention, the GPS using the position data thinning device for positioning is used.
Since the number of satellites is calculated and whether to transmit the position is determined based on the number of satellites used for positioning, rescue is performed by detecting position data with a large number of positioning satellites and transmitting only that position data. The time required to transmit location data to an institution or the like can be reduced.

(Eighth Embodiment) An eighth embodiment of the present invention detects whether positioning by a GPS satellite is successful, and determines whether or not to transmit a position based on the presence or absence of positioning by a GPS satellite. Is a position data thinning device.

FIG. 8 is a functional block diagram showing the configuration of the position data thinning device according to the eighth embodiment of the present invention. In FIG. 8, the position calculating means 1 and the satellite positioning presence / absence detecting means 7 are the same as those in the first or fourth embodiment.

The operation of the position data thinning device according to the eighth embodiment of the present invention configured as described above will be described. The operation of the position calculating means 1 is the same as in the first embodiment. The operation of the satellite positioning presence / absence detecting means 7 is the fourth.
This is the same as the embodiment.

The position recording means 4 stores the position obtained by the position calculating means 1 and the presence / absence of positioning obtained by the satellite positioning presence / absence detecting means 7 or the ratio of positioning by a satellite in a certain time, for example, in a memory or the like. Record on a recording medium.

When transmitting position data recorded in the past T (T may be variable) time (or minute, second) from a certain point in time to, for example, a rescue agency, the position transmission determining means 8 Location and the presence or absence of positioning, or
The information of the ratio of the positioning by the satellite in a certain fixed time is read. The position transmission determining means 8 determines that the position accuracy of the calculated position is low when the positioning by the satellite is not performed, or when the ratio of the positioning by the satellite in a certain time is less than a certain threshold. Are not output to the position transmitting means 9. Conversely, the position transmission determining means 8 determines that the accuracy of the calculated position is high when the positioning by the satellite is performed or when the ratio of the positioning by the satellite in a certain time is equal to or more than a certain threshold. Then, it outputs to the position transmitting means 9. The operation of the position transmitting means 9 is the same as that of the fifth embodiment.

As described above, in the eighth embodiment of the present invention, the position data thinning device detects whether the positioning by the GPS satellite is successful and determines whether or not to transmit the position by the GPS satellite. Since it is determined based on the presence / absence, it detects position data that is frequently measured by GPS or that is frequently measured by GPS within a certain period of time, and transmits only that position data to the rescue agency. The time required to transmit data can be reduced.

(Ninth Embodiment) In a ninth embodiment of the present invention, the moving distance or the accumulated traveling distance at the calculated position is recorded, and it is determined whether or not to transmit the calculated position at a certain time. This is a position data thinning-out device that is determined based on the moving distance up to.

FIG. 9 is a functional block diagram showing the configuration of the position data thinning device according to the ninth embodiment of the present invention. In FIG. 9, a distance recording means 10 is a means for recording a moving distance or a cumulative traveling distance at a measured position.

The operation of the position data thinning device according to the ninth embodiment of the present invention configured as described above will be described. The operation of the position calculating means 1 is the same as in the first embodiment. The position recording unit 4 records the position obtained by the position calculation unit 1 in, for example, a memory or a recording medium. The distance recording means 10 records the moving distance or the accumulated traveling distance at the measured position.

When transmitting position data recorded from a certain point in the past to a rescue agency, for example,
The position transmission determining means 8 reads the recorded position and the moving distance or the accumulated traveling distance. The position transmission determining means 8 selects position data to be output to the position transmitting means 9 for each traveling distance reaching the position at a certain point in time.

For example, suppose that the position and the moving distance are recorded every second, and the position data is sent retroactively from the time when the accident occurred. First, based on the position at the time of occurrence of the accident, a moving distance to reach the position is determined for each position. Next, the period for sampling the position data to be transmitted is changed according to the moving distance to the accident occurrence point. For example, the position data is transmitted every 1 second from the accident occurrence position to a position 1 km before the position. The position data is transmitted every 2 seconds from the position 1 km before the accident position to the position 2 km before the accident position. The position data is transmitted every 4 seconds from the position 2 km before the accident occurrence position to the position 4 km before the accident occurrence position.

As described above, in the ninth embodiment of the present invention, the position data thinning device records the moving distance or the accumulated traveling distance at the calculated position and determines whether to transmit the calculated position. Since the determination is made based on the distance traveled until the point in time, the location data is large near the reporting location (accident location), and the location data can be reduced as the distance from the reporting location increases. Can be shortened.

[0065]

As is apparent from the above description, according to the present invention, the position data thinning device is provided with a position calculation for calculating the position of a moving body using at least one of an absolute position detection sensor, a distance sensor and an angular velocity sensor. Means, position recording means for recording the calculated position data, distance recording means for recording the moving distance or the accumulated traveling distance at the calculated position, and a plurality of position data calculated retroactively from a certain point in time and wirelessly. Since it is configured to include the position transmitting means for transmitting and the position transmission determining means for determining whether to transmit the position data based on the moving distance until reaching a certain point in time, the position data with high accuracy is detected and the position is determined. By recording only the data in the memory, it is possible to reduce the memory amount of the position data to be recorded for displaying the traveling locus, and Effect that can shorten the time it takes to send the data. In addition, since the position data is large near the reporting position and the position data can be reduced as the position is farther from the reporting position, the time required for transmitting the position data to a rescue agency or the like can be shortened.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a position data thinning device according to a first embodiment of the present invention;

FIG. 2 is a schematic block diagram of a position data thinning device according to a second embodiment of the present invention;

FIG. 3 is a schematic block diagram of a position data thinning device according to a third embodiment of the present invention;

FIG. 4 is a schematic block diagram of a position data thinning device according to a fourth embodiment of the present invention;

FIG. 5 is a schematic block diagram of a position data thinning device according to a fifth embodiment of the present invention;

FIG. 6 is a schematic block diagram of a position data thinning device according to a sixth embodiment of the present invention;

FIG. 7 is a schematic block diagram of a position data thinning device according to a seventh embodiment of the present invention;

FIG. 8 is a schematic block diagram of a position data thinning device according to an eighth embodiment of the present invention;

FIG. 9 is a schematic block diagram of a position data thinning device according to a ninth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Position calculation means 2 Position accuracy calculation means 3 Position record judgment means 4 Position recording means 5 Azimuth accuracy calculation means 6 Positioning satellite number calculation means 7 Satellite positioning presence / absence detection means 8 Position transmission judgment means 9 Position transmission means 10 Distance recording means

Claims (1)

[Claims] 1. A position calculating means for calculating a position of a moving body using at least one of an absolute position detecting sensor, a distance sensor, and an angular velocity sensor; a position recording means for recording calculated position data; Distance recording means for recording the moving distance or the accumulated traveling distance, position transmitting means for wirelessly transmitting a plurality of position data calculated from a certain point in time to the past, and whether to transmit the position data at a certain point in time. A position data thinning device comprising: a position transmission determining means for determining the distance based on a moving distance until the position is reached.